Range-wide Phylogeography of a Nivicolous Protist Didymium nivicola Meyl. (Myxomycetes, Amoebozoa): Striking Contrasts Between the Northern and the Southern Hemisphere

Genetic structure of the protist Physarum albescens (Amoebozoa) revealed by multiple markers and genotyping by sequencing

“…On the one hand, such patterns of multiple cryptic species within morphospecies seem to be common in myxomycetes and may represent a general mode of evolution in this group: all hitherto investigated morphospecies turned out to be complexes of several cryptic species (Aguilar et al, 2014; Dagamac et al, 2017; Feng & Schnittler, 2015; Janik et al, 2020; Leontyev et al, 2015; Shchepin et al, 2016). This means that we should expect the real number of myxomycete species to be several times bigger than c. 1050 currently recognized species (Lado, 2005–2021).…”

“…albescens were obtained using the R package iNEXT 2.0.20 (Hsieh et al, 2016). In addition, the same analyses were performed for six other myxomycete species based on data from published phylogeographic studies: Badhamia melanospora , Didymium nivicola , Hemitrichia serpula , Lepidoderma chailletii , Meriderma atrosporum , Trichia varia (Aguilar et al, 2014; Dagamac et al, 2017; Feng et al, 2016; Feng & Schnittler, 2015; Janik et al, 2020; Shchepin et al, 2016).…”

“…In the Sierra Nevada and Khibiny Mts., members of some putatively clonal groups were found in different valleys, so their distribution cannot be explained by a passive drift of pieces of plasmodia with streams of water running down from melting snow patches. This could be a sign of asexual lineages dispersing via airborne spores, as suggested for Didymium nivicola (Janik et al, 2020). A second possible explanation (as well speculative) could be that these genetically nearly identical specimens result from repeated mating of a few dominating myxamoebal strains that are widely distributed within a large area and persist from year to year.…”

“…Dagamac et al (2017) analysed two‐gene data (SSU and EF1A) and revealed four putative cryptic species in Hemitrichia serpula with subtle morphological differences. Finally, several large phylogroups were found within Didymium nivicola in SSU and EF1A phylogenies, with striking differences in genetic diversity between the Northern and the Southern Hemisphere (Janik et al, 2020).…”

A workflow for low-cost automated image analysis of myxomycete spore numbers, size and shape

“…Spore size is an important criterion in taxonomy. Therefore, exact measurements may help to identify cryptic biological species ( i.e., reproductively isolated sympatric populations), for example in myxomycetes, as found in a number of molecular studies ( Feng & Schnittler, 2015 ; Feng, Bhanu & Heraty, 2016 ; Feng et al, 2016 ; Shchepin, Novozhilov & Schnittler, 2016 ; Dagamac et al, 2017 ; Janik, Lado & Ronikier, 2020 ). Figure 5C shows such a case, where colonies of two different phylogroups ( i.e., putative biological species) growing together differ in spore size distribution.…”